[wpilibj] Fix java async interrupts (#3559)

wpilibj/src/test/java/edu/wpi/first/wpilibj/InterruptTest.java

@@ -0,0 +1,46 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+package edu.wpi.first.wpilibj;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import edu.wpi.first.wpilibj.simulation.DIOSim;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicInteger;
+import org.junit.jupiter.api.Test;
+
+public class InterruptTest {
+  @Test
+  void testAsynchronousInterrupt() {
+    AtomicBoolean hasFired = new AtomicBoolean(false);
+    AtomicInteger counter = new AtomicInteger(0);
+
+    try (DigitalInput di = new DigitalInput(0);
+        AsynchronousInterrupt interrupt =
+            new AsynchronousInterrupt(
+                di,
+                (a, b) -> {
+                  counter.incrementAndGet();
+                  hasFired.set(true);
+                })) {
+      interrupt.enable();
+      Timer.delay(0.5);
+      DIOSim digitalSim = new DIOSim(di);
+      digitalSim.setValue(false);
+      Timer.delay(0.01);
+      digitalSim.setValue(true);
+      Timer.delay(0.01);
+
+      int count = 0;
+      while (!hasFired.get()) {
+        Timer.delay(0.005);
+        count++;
+        assertTrue(count < 1000);
+      }
+      assertEquals(1, counter.get(), "The interrupt did not fire the expected number of times");
+    }
+  }
+}